TWI595689B - Piezoelectric device, liquid ejection head, and method of manufacturing piezoelectric device - Google Patents

Description

Piezoelectric device, liquid ejecting head, and manufacturing method of piezoelectric device

The present invention relates to a piezoelectric device including a first substrate on which an empty chamber is formed, and a piezoelectric device, a liquid ejecting head, and a piezoelectric device, which are laminated on a piezoelectric element on a vibrating plate.

The piezoelectric device is provided with a piezoelectric element and is applied to various liquid ejecting apparatuses, vibration sensors, and the like. For example, in the liquid ejecting apparatus, various liquids are ejected (sprayed) from the liquid ejecting head by the piezoelectric device. As the liquid ejecting apparatus, there is an image recording apparatus such as an ink jet printer or an ink jet type plotter, but recently, it has been applied to various manufacturing apparatuses by utilizing a feature that a very small amount of liquid can be accurately attached to a specific position. . For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode of an organic EL (Electro Luminescence) display or an FED (Face Light Emitting Display), or the like, and a biochip (bio Wafer manufacturing apparatus for chemical components). Further, liquid ink is ejected into the recording head for the image recording apparatus, and R (Red: red), G (Green: green), and B (Blue: blue) are ejected in the color material ejecting head for the display manufacturing apparatus. a solution of each color material. Further, a liquid electrode material is ejected from the electrode material ejecting head for the electrode forming apparatus, and a solution of the biological organic substance is ejected in the bioorganic material ejecting head for the wafer manufacturing apparatus.

The liquid ejecting head using the above piezoelectric device includes a plurality of nozzles, a pressure chamber corresponding thereto, and a piezoelectric element. The pressure chamber is formed by forming a substrate (actuator substrate) by etching a pressure chamber, and a part thereof is partitioned by a vibrating plate having flexibility. On the vibrating plate A piezoelectric element in which a lower electrode layer, a piezoelectric layer including a piezoelectric material such as lead zirconate titanate (PZT), and a top electrode layer are laminated is formed. Further, a communication substrate is joined to the side opposite to the pressure chamber forming substrate, and a pressure chamber and a nozzle are communicated via a nozzle communication path formed in the communication substrate. In the liquid ejecting head configured as described above, the piezoelectric element corresponding to each nozzle is deformed by the application of a voltage, and a liquid is generated in a pressure in the corresponding pressure chamber to eject the liquid from each nozzle (for example, refer to Patent Document 1). .

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2015-089614

However, with the miniaturization of the liquid ejecting head, the thickness of the substrate in which the pressure chamber is formed tends to be thin. Therefore, the pressure chamber forming substrate is easily deformed due to the low rigidity. In particular, in the pressure chamber forming the separator in which the pressure chambers adjacent to each other in the substrate are formed, the size of the pressure chambers in the arrangement direction of the pressure chambers tends to be small due to the narrow pitch of the pressure chambers which have been increased in density in recent years. Therefore, the rigidity of the partition of the zone pressure chamber tends to be further lowered. As a result, the pressure chamber forming substrate is easily deformed, and the pressure chamber forming substrate faces away from the communicating substrate bonded thereto. For example, as in the recording head 100 illustrated in Fig. 12, a plurality of laminated piezoelectric elements 90 have an initial state (not applied) due to a tensile force or the like generated by a layer (film) constituting the piezoelectric element 90. In the state of the voltage, the lower side is bent toward the side opposite to the pressure chamber 91. If the bending is transmitted to a portion of the pressure chamber forming substrate 93 around the division pressure chamber 91 via the vibration plate 92, the pressure chamber forming the substrate 93 (i.e., the partition portion of the division pressure chamber 91) is formed in the peripheral portion of the pressure chamber 91. It is deformed in such a manner as to warp toward the piezoelectric element 90 side. As a result, the bonding pressure chamber forming substrate 93 and the interconnecting substrate 94 are peeled off, and a part of the pressure chamber forming substrate 93 is peeled off from the communicating substrate 94. This problem also exists in a piezoelectric device including a first substrate in which a piezoelectric element is laminated on an empty chamber and a second substrate bonded thereto.

The present invention has been made in view of the above circumstances, and an object of the invention is to provide a piezoelectric device, a liquid ejecting head, and a piezoelectric device capable of suppressing peeling of a first substrate forming a blank and a second substrate laminated on a first substrate. Manufacturing method.

In order to achieve the above object, a piezoelectric device according to the present invention includes: a first substrate formed with an empty chamber; a diaphragm that partitions a surface on one side of the empty chamber; and a piezoelectric element a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated from the side of the vibrating plate on a side opposite to the empty chamber; and the second substrate is laminated on the first substrate The side opposite to the vibrating plate side; and at least a portion of the opening peripheral region of the empty chamber of the first substrate is thicker than a region outside the opening peripheral region.

According to this configuration, even if the piezoelectric element is deformed toward the side opposite to the diaphragm, peeling of the first substrate and the second substrate can be suppressed. As a result, the reliability of the piezoelectric device can be improved.

Further, in the above configuration, it is preferable that the entire circumference of the opening peripheral region is thicker than the outer region of the opening peripheral region.

According to this configuration, peeling of the first substrate and the second substrate can be further suppressed. As a result, the reliability of the piezoelectric device can be further improved.

Furthermore, the piezoelectric device of the present invention is characterized by comprising: a first substrate having an empty chamber; a vibration plate dicating a surface on one side of the empty chamber; and a piezoelectric element attached to the vibration plate On the opposite side of the empty chamber, the first electrode layer, the piezoelectric layer, and the second electrode layer are sequentially stacked from the side of the vibrating plate; and the second substrate is laminated on the side of the first substrate opposite to the vibrating plate And a side of the first substrate is gradually thicker toward the thickness of the empty chamber.

According to this configuration, peeling of the first substrate and the second substrate can be suppressed. As a result, the reliability of the piezoelectric device can be improved.

Further, the liquid ejecting head according to the present invention includes the piezoelectric device of each of the above configurations, and a nozzle that communicates with the empty chamber.

Moreover, the method for manufacturing a piezoelectric device according to the present invention has been proposed in order to achieve the above object, the piezoelectric device comprising: a first substrate having an empty chamber; and a vibration plate partitioning a surface on one side of the empty chamber; a piezoelectric element which is formed on a side opposite to the empty chamber of the vibrating plate, and sequentially forms a first electrode layer, a piezoelectric layer, and a second electrode layer from the vibrating plate side; and a second substrate The method of manufacturing a piezoelectric device includes a piezoelectric element forming step of forming a substrate of the first substrate and the vibrating plate on the side opposite to the vibrating plate side of the first substrate. a surface of the side of the vibrating plate forming the piezoelectric element; and a polishing step of pressing the region of the original substrate from the piezoelectric element away from the piezoelectric element in a thickness direction Polishing the substrate original sheet on the side opposite to the element side, so that the thickness of the substrate original sheet in the unpressed region is thicker than the thickness of the substrate original sheet in the pressed region; the empty chamber forming step is to be ground The above substrate a region having a thick plate thickness, that is, a region corresponding to the piezoelectric element, forming the empty chamber, the substrate original sheet being the first substrate and the vibrating plate, and a substrate bonding step on the first substrate The second substrate is bonded to the side opposite to the piezoelectric element side.

Further, in the polishing step of the above method, it is preferable that the unpressed region of the substrate original sheet is raised toward the side opposite to the piezoelectric element side from the pressed region.

According to these methods, peeling of the first substrate and the second substrate can be suppressed, and a piezoelectric device having high reliability can be produced.

1‧‧‧Printer

2‧‧‧Recording media

3‧‧‧record head

4‧‧‧ bracket

5‧‧‧ bracket moving mechanism

6‧‧‧Transportation agency

7‧‧‧Ink 匣

8‧‧‧ Timing belt

9‧‧‧ pulse motor

10‧‧‧guides

17‧‧‧Pressure generating unit

18‧‧‧ runner unit

19‧‧‧ head shell

20‧‧‧ Liquid introduction route

21‧‧‧Nozzle plate

22‧‧‧Nozzles

23‧‧‧Compatible substrate

24‧‧‧Connected substrate

25‧‧‧Common liquid room

27‧‧‧ vacant department

28‧‧‧ supply port

29‧‧‧ Pressure chamber forming substrate

29'‧‧‧ Pressure chamber forming substrate

30‧‧‧ Pressure chamber

30'‧‧‧ Pressure chamber

31‧‧‧Vibration plate

32‧‧‧Piezoelectric components

33‧‧‧ Sealing plate

33a‧‧‧Top Board

33b‧‧‧ Sidewall

35‧‧‧Nozzle communication road

36‧‧‧ lower electrode layer

37‧‧‧piezoelectric layer

38‧‧‧Upper electrode layer

39‧‧‧metal layer

40‧‧‧Lead electrode

41‧‧‧ Piezoelectric component storage

43‧‧‧ substrate original film

43'‧‧‧ substrate original film

44‧‧‧Pushing substrate

44a‧‧‧empty department

44b‧‧‧ Pressing Department

90‧‧‧Piezoelectric components

91‧‧‧ Pressure chamber

92‧‧‧vibration board

93‧‧‧ Pressure chamber forming substrate

94‧‧‧Connected substrate

100‧‧‧record head

Ae‧‧‧Open Peripheral Area

Ta‧‧‧distance

Ta'‧‧‧ plate thickness

Tb‧‧‧ plate thickness

Figure 1 is a perspective view showing the construction of a printer.

Fig. 2 is a cross-sectional view showing an enlarged portion of the configuration of the recording head.

Fig. 3 is a plan view showing the substrate formed by the pressure chamber from the side of the vibrating plate.

Figure 4 is a cross-sectional view taken along line A-A of Figure 3.

Figure 5 is a cross-sectional view taken along line B-B of Figure 3.

6(a) and 6(b) are schematic views showing the steps of manufacturing the recording head.

7(a) and 7(b) are schematic views showing the steps of manufacturing the recording head.

8(a) to (c) are schematic views showing the steps of manufacturing the recording head.

Fig. 9 is a plan view showing the pressure chamber forming substrate of the recording head of the second embodiment viewed from the side of the diaphragm.

Figs. 10(a) and (b) are schematic views showing the steps of manufacturing the recording head of the second embodiment.

11(a) to 11(c) are schematic diagrams showing the steps of manufacturing the recording head of the second embodiment.

Fig. 12 is a cross-sectional view showing an enlarged portion of the configuration of the prior recording head.

Hereinafter, embodiments for carrying out the invention will be described with reference to the accompanying drawings. In the following embodiments, the preferred embodiments of the present invention are variously limited, but the scope of the present invention is not limited to the following description, and is not limited to the meaning of the present invention. The same. In the following, an ink jet printer (hereinafter referred to as a liquid jet apparatus) which is an ink jet type recording head (hereinafter referred to as a recording head) which is a type of liquid ejecting head including the piezoelectric device of the present invention is mounted. Table machine) is explained as an example.

The configuration of the printer 1 will be described with reference to Fig. 1 . The printer 1 is a device that ejects ink (one of liquids) on the surface of a recording medium 2 (one of the objects to be ejected) such as recording paper to record an image or the like. The printer 1 is provided with a recording head 3 and a bracket on which the recording head 3 is mounted 4. The carriage moving mechanism 5 that moves the carriage 4 in the main scanning direction, and the conveyance mechanism 6 that transfers the recording medium 2 in the sub-scanning direction. Here, the ink is stored in the ink cartridge 7 as a liquid supply source. The ink cartridge 7 is detachably attached to the carriage 4, that is, the recording head 3. Alternatively, the ink cartridge may be disposed on the main body side of the printer, and the ink cartridge may be supplied to the recording head through the ink supply tube.

The carriage moving mechanism 5 is provided with a timing belt 8. Further, the timing belt 8 is driven by a pulse motor 9 such as a DC motor. Therefore, when the pulse motor 9 is actuated, the carriage 4 is guided by the guide bar 10 mounted on the printer 1, and reciprocates in the main scanning direction (the width direction of the recording medium 2). The position of the carriage 4 in the main scanning direction is detected by a linear encoder (not shown) which is one of the position information detecting mechanisms. The linear encoder transmits its detection signal, that is, an encoder pulse (one of position information), to the control unit of the printer 1.

Fig. 2 is a cross-sectional view showing the configuration of a main portion of the recording head 3. 3 is a schematic view of the pressure chamber forming substrate 29 constituting the recording head 3 from the side of the diaphragm 31 (the side of the sealing plate 33). In addition, it is shown by the sealing plate 33 in FIG. 4 is an enlarged view of a section A-A of FIG. 3, and FIG. 5 is an enlarged view of a section B-B of FIG. As shown in FIG. 2, the recording head 3 of the present embodiment includes a pressure generating unit 17 and a flow path unit 18, and is attached to the head case 19 in a state in which the members are stacked. The flow path unit 18 has a nozzle plate 21, a compatible substrate 23, and a communication substrate 24 (corresponding to the second substrate of the present invention). Further, the pressure generating unit 17 laminates and unitizes the pressure chamber forming substrate 29 (corresponding to the first substrate of the present invention) in which the pressure chamber 30 is formed, the diaphragm 31, the piezoelectric element 32, and the sealing plate 33. Further, each unit is joined by an adhesive.

The head case 19 is, for example, a box-shaped member made of synthetic resin, and the communication board 24 to which the pressure generating unit 17 is joined is fixed to the bottom surface side. On the lower surface side of the head case 19, a housing portion 27 recessed in a rectangular parallelepiped shape from the lower surface to the height direction of the head case 19 is formed. When the flow path unit 18 is joined in a state of being positioned on the lower surface of the head case 19, the pressure generating unit 17 laminated on the communication substrate 24 is housed in the storage space portion 27. Also, in the shape of the head shell 19 A liquid introduction path 20 is formed. The liquid introduction path 20 is for introducing an empty portion of the ink from the ink cartridge 7 side. The ink that has flowed into the liquid introduction path 20 is introduced into the common liquid chamber 25 (described later) that communicates with the substrate 24.

The communication substrate 24 bonded to the lower surface side of the head case 19 is, for example, a plate material made of a single crystal germanium substrate (hereinafter also simply referred to as a germanium substrate). In the communicating substrate 24, the empty portions of the nozzle communication path 35 and the common liquid chamber 25 are formed by anisotropic etching or the like. The nozzle communication passage 35 is connected to a flow passage of the nozzle 22 and the pressure chamber 30, which will be described later, and is formed in each of the nozzles 22. Each of the nozzle communication passages 35 communicates with one end portion of the longitudinal direction of the respective pressure chambers 30. Further, the common liquid chamber 25 is extended in the nozzle row direction (in other words, in the direction in which the pressure chambers 30 are arranged), and the common pressure ink is introduced into each of the pressure chambers 30. The common liquid chamber 25 communicates with the liquid introduction path 20 and introduces ink from the liquid introduction path 20. The common liquid chamber 25 and each of the pressure chambers 30 are connected to each other via a supply port 28 that is individually provided in each of the pressure chambers 30. Each of the supply ports 28 communicates with the other end of the longitudinal direction of the respective pressure chambers 30. Therefore, the ink in the common liquid chamber 25 is distributed and supplied to the pressure chambers 30 through the supply port 28.

The nozzle plate 21 and the compatible substrate 23 are joined to the lower surface of the communication substrate 24 (the surface opposite to the head case 19). The nozzle plate 21 is provided with a plate material of a plurality of nozzles 22, for example, made of a ruthenium substrate. The nozzles 22 are formed in a line shape in the sub-scanning direction to constitute a nozzle row. The nozzle row is arranged in a row from the nozzle 22 on one end side to the nozzle 22 on the other end side in a distance corresponding to the dot formation density. In particular, in the present embodiment, a narrow pitch (for example, a 42.4 μm pitch (that is, 600 dpi)) is formed so that a high-quality image can be formed. The nozzle plate 21 is joined to a central portion of the lower surface of the communication substrate 24 in a state in which the nozzles 22 and the nozzle communication passages 35 of the communication substrate 24 communicate with each other. The compatibility substrate 23 is a flexible member joined to the lower surface of the substrate 24 and joined to the opening of the common liquid chamber 25. The compatible substrate 23 functions to absorb the pressure change of the ink in the common liquid chamber 25.

The pressure chamber forming substrate 29 that is connected (laminated) to the upper surface of the communication substrate 24 (the surface opposite to the nozzle plate 21) is made of, for example, a tantalum substrate. In particular, in the present embodiment, by The ruthenium substrate is polished as described later, and the thickness of the pressure chamber formation substrate 29 is formed to be, for example, about 40 to 50 μm. The substrate 29 is formed in the pressure chamber, and the pressure chamber 30 (corresponding to the empty chamber of the present invention) that penetrates the pressure chamber forming substrate 29 in the thickness direction is formed in plural with the same distance from the nozzle 22. In the present embodiment, as shown in FIG. 3, in a plan view (a state observed from the surface of the pressure chamber forming substrate 29 or a state observed from the laminated direction of the constituent members), it is formed to be orthogonal to the nozzle row direction. The shape of the strip is roughly parallel to the shape of the four sides. Further, as shown in FIG. 2 and FIG. 4, in the longitudinal direction of the pressure chamber 30, the inner wall of the pressure chamber 30 is partitioned to form a substrate with respect to the pressure chamber so as to expand outward from the upper surface side toward the lower surface side. The surface of 29 is inclined. Further, the partitions of the pressure chambers 30 forming the substrate 29 are formed to be thicker than the other portions. Details on this point will be described later.

The vibrating plate 31 is a flexible film which is laminated on the upper surface of the pressure chamber forming substrate 29 and which partitions the surface (upper surface) on one side of the pressure chamber 30. The diaphragm 31 includes, for example, an elastic film containing cerium oxide (SiO ₂ ) and an insulator film containing zirconium oxide (ZrOx) formed on the elastic film. The portion of the vibrating plate 31 that partitions the pressure chamber 30, that is, the portion that is closed to the upper portion of the space of the pressure chamber 30, is allowed to bend and deform in a direction away from or close to the nozzle 22 with the bending deformation of the piezoelectric element 32. The area. Further, in the present embodiment, the vibrating plate 31 and the pressure chamber forming substrate 29 are separately formed by different members. However, the present invention is not limited thereto, and the vibrating plate and the pressure chamber forming substrate may be integrally formed. For example, a pressure chamber may be formed from the lower surface side of the substrate on which the substrate is formed by the pressure chamber, and the thin portion having a thin thickness on the upper surface side is etched to the middle of the thickness direction of the substrate. In this case, the remaining thin portion corresponds to the diaphragm.

A piezoelectric element 32 is formed on the side of the vibrating plate 31 opposite to the pressure chamber 30 corresponding to the pressure chamber 30. The piezoelectric element 32 of the present embodiment is a piezoelectric element of a so-called bending mode. As shown in FIG. 2, the piezoelectric element 32 is formed by laminating a metal lower electrode layer 36 (corresponding to the first electrode of the present invention) by a film formation technique from the side of the vibrating plate 31, and contains zirconium titanate. a piezoelectric layer 37 such as lead (PZT) or a metal upper electrode layer 38 (corresponding to the present invention) The second electrode). That is, the piezoelectric element 32 is a portion where piezoelectric strain is generated in the piezoelectric layer 37 by application of a voltage to the lower electrode layer 36 and the upper electrode layer 38. As shown in FIG. 3, the piezoelectric element 32 of the present embodiment extends beyond the end in the longitudinal direction of the pressure chamber 30 to a position distant from the pressure chamber 30 to the outside. On the other hand, both end portions in the short-side direction are formed on the inner side from the end in the short-side direction of the pressure chamber 30.

In the present embodiment, the lower electrode layer 36 and the piezoelectric layer 37 are patterned in each of the pressure chambers 30, and the upper electrode layer 38 is patterned across a plurality of pressure chambers 30. That is, the lower electrode layer 36 is an individual electrode of each of the pressure chambers 30. The upper electrode layer 38 serves as a common electrode common to a plurality of piezoelectric elements 32. Further, in the present embodiment, as shown in FIG. 2, an adhesion layer (not shown) containing titanium (Ti) or nickel (Ni) is interposed on the upper electrode layer 38, and gold (Au) or the like is laminated. Metal layer 39. The metal layer 39 is formed at both ends in the longitudinal direction of the piezoelectric element 32, and is laminated across the boundary between the inner side and the outer side in the longitudinal direction of the pressure chamber 30. By the metal layer 39, deformation (displacement) of the piezoelectric element 32 in the boundary between the inner side and the outer side of the pressure chamber 30 is suppressed, and damage of the piezoelectric element 32 due to stress concentration is suppressed. Further, a lead electrode 40 is connected to an end portion of one side of the piezoelectric element 32 (on the side of the central portion of the recording head 3). The lead electrode 40 is extended to the outer side of the sealing plate 33, and is connected to a flexible cable (not shown). Further, the lower electrode layer 36 may be a common electrode common to the plurality of piezoelectric elements 32, and the upper electrode layer 38 may be formed as an individual electrode of each of the piezoelectric elements 32.

A sealing plate 33 is disposed on the upper surface of the pressure chamber forming substrate 29 on which the piezoelectric element 32 is formed. The sealing plate 33 is made of, for example, glass, a ceramic material, a single crystal germanium substrate, a metal, a synthetic resin, or the like. Inside the sealing plate 33, a piezoelectric element housing portion 41 having a size that does not impede the driving of the piezoelectric element 32 is formed in a region opposed to each piezoelectric element 32. In other words, the piezoelectric element housing portion 41 of the sealing plate 33 is partitioned by the top plate portion 33a opposed to the piezoelectric element 32 and the side wall portion 33b extending from the outer periphery of the top plate portion 33a to the piezoelectric element 32 side. The side wall portion 33b is disposed along the arrangement direction of the piezoelectric elements 32 (nozzle row direction) so that the piezoelectric elements 32 arranged in the piezoelectric element housing portion 41 are all accommodated. The extension is extended to the outer side of the column of the piezoelectric elements 32. In addition, the lower end surface of the side wall portion 33b is joined to the upper surface of the pressure chamber forming substrate 29 in a state in which the piezoelectric element 32 is accommodated in the piezoelectric element housing portion 41.

In the recording head 3 configured as described above, the ink from the ink cartridge 7 is introduced into the pressure chamber 30 via the liquid introduction path 20, the common liquid chamber 25, and the supply port 28. In this state, the drive signal from the control unit is supplied to the piezoelectric element 32 via the flexible cable, the lead electrode 40, and the like, and the piezoelectric element 32 is driven. Thereby, the volume of the pressure chamber 30 fluctuates, and a pressure fluctuation occurs in the pressure chamber 30. By using this pressure fluctuation, ink droplets are ejected from the nozzle 22 via the nozzle communication path 35. Further, in the present embodiment, in each of the layers constituting the recording head 3, the combination of the communication substrate 24, the pressure chamber forming substrate 29, the vibration plate 31, and the piezoelectric element 32 corresponds to the piezoelectric device of the present invention.

Next, the pressure chamber forming substrate 29 of the present embodiment will be described in detail. As shown in FIGS. 4 and 5, the peripheral peripheral edge area Ae of each pressure chamber 30 of the pressure chamber forming substrate 29 (the hatched area of FIG. 3, the entire circumference of the opening periphery of each pressure chamber 30) is larger than the peripheral peripheral area of the opening. The plate thickness of the outer side of Ae is formed to be thicker. In particular, in the present embodiment, the thickness of the pressure chamber 30 is gradually increased. As will be described in more detail, as shown in FIGS. 4 and 5, the piezoelectric element 32 is in an initial state due to the tensile force generated by the layer (for example, the metal layer 39 or the like) constituting the piezoelectric element 32 (the upper electrode layer is not 38 and the state in which the lower electrode layer 36 is applied with a voltage) are bent toward the side opposite to the pressure chamber 30, so that the top plate surface of the substantially central portion of the pressure chamber 30 (the vibration plate 31 opened at the upper portion of the plugging pressure chamber 30) faces upward ( The sealing plate 33 side is raised. That is, the distance between the lower surface of the vibrating plate 31 at the substantially central portion of the pressure chamber 30 and the upper surface of the communicating substrate 24 (i.e., the height of the substantially central portion of the pressure chamber 30) ta and the peripheral peripheral region of the pressure chamber forming substrate 29 The plate thickness tb of the outer side region of Ae (for example, the plate thickness at the position where the side wall portion 33b of the sealing plate 33 is disposed) is larger (thickness).

Further, the upper surface of the pressure chamber forming substrate 29 of the opening edge of the pressure chamber 30 is raised upward. That is, the pressure chamber of the opening edge of the pressure chamber 30 forms the thickness of the substrate 29 (in other words, The height of the side wall of the division pressure chamber 30 or the height of the end of the pressure chamber 30) ta' is about 3 μm thicker than the thickness tb of the area outside the opening peripheral area Ae. In the present embodiment, the thickness ta' of the pressure chamber forming substrate 29 at the opening edge of the pressure chamber 30 and the distance ta from the lower surface of the vibrating plate 31 at the substantially central portion of the pressure chamber 30 to the upper surface of the communicating substrate 24 are substantially Same, or slightly smaller (lower). Further, as shown in Fig. 4, the side wall of the longitudinal direction of the pressure chamber 30 is inclined so as to expand outward from the upper surface side toward the lower surface side, and the pressure chamber forming the substrate 29 of the opening edge of the pressure chamber 30 as described herein is formed. The plate thickness ta' is a distance from the upper edge side opening edge (inner opening edge) vertically downward to a position orthogonal to the imaginary plane extending from the lower surface of the pressure chamber forming substrate 29. That is, the thickness of the pressure chamber forming substrate 29 as referred to herein also includes the portion where the pressure chamber forming substrate 29 is cut to include a space in a part thereof.

Further, the upper surface of the pressure chamber forming substrate 29 of the opening edge of the pressure chamber 30 is inclined downward toward the outside (the outer peripheral side of the pressure chamber forming substrate 29). That is, the thickness of the pressure chamber forming substrate 29 is gradually thinned toward the outside from the opening edge of the pressure chamber 30 having the thickest thickness. The pressure chamber forms a region in which the thickness of the substrate 29 is thicker than other regions, and corresponds to the peripheral edge region Ae. Further, the region other than the opening peripheral region Ae of the pressure chamber 30 of the present embodiment is set to have substantially the same plate thickness tb until the end portion (outer periphery) of the pressure chamber forming substrate 29. Further, in the present embodiment, the opening edge in the longitudinal direction of the pressure chamber 30 and the opening edge in the short-side direction of the pressure chamber 30 have the same plate thickness tb, but may have different plate thicknesses.

In this manner, the thickness of the pressure chamber forming substrate 29 in which the thickness of the pressure chamber forming substrate 29 of the opening peripheral region Ae of the pressure chamber 30 is set to be outside the opening peripheral edge area Ae is thicker, so even in the initial state The piezoelectric element 32 is deformed toward the side opposite to the diaphragm 31, and also suppresses deformation of the opening peripheral region Ae following the deformation of the piezoelectric element 32. Therefore, in the opening peripheral region Ae, peeling of the adhesive between the bonding pressure chamber forming substrate 29 and the communication substrate 24 can be suppressed, and the two substrates can be peeled off. Thereby, it is possible to suppress a situation in which the portion where the pressure chamber forming substrate 29 and the communicating substrate 24 are separated from each other by the ink, and the pressure between the pressure chamber forming substrate 29 and the communicating substrate 24 is lowered. Moreover, the adhesive capable of suppressing peeling becomes a foreign matter The reason is that the nozzle 22 is clogged or the ink droplets are flying. As a result, the reliability of the piezoelectric device can be improved. Further, even if the piezoelectric element 32 is repeatedly driven, peeling of the pressure chamber forming substrate 29 from the communication substrate 24 can be suppressed. Further, since the thickness of the pressure chamber forming substrate 29 is gradually increased toward the pressure chamber 30, it is possible to suppress the poor bonding of the vibrating plate 31 or the communicating substrate 24 due to the step formation of the pressure chamber forming substrate 29. .

Next, a method of manufacturing a portion corresponding to the piezoelectric device, that is, a portion in which the communication substrate 24, the pressure chamber forming substrate 29, the vibration plate 31, and the piezoelectric element 32 are laminated in the above-described recording head 3 will be described. First, a substrate (for example, a tantalum substrate) that serves as the pressure chamber forming substrate 29 is formed on a layer that serves as the vibrating plate 31 (for example, a film in which zirconium oxide (ZrOx) is laminated on SiO ₂ ), and is formed. The pressure substrate is formed on the substrate 29 and the substrate original sheet 43 of the diaphragm 31. When the substrate original sheet 43 is formed, it moves to the piezoelectric element forming step. In the piezoelectric element forming step, as shown in FIG. 6(a), the piezoelectric element 32 is formed on the surface of the substrate original sheet 43 which is the side of the vibrating plate 31. Specifically, a metal film to be the lower electrode layer 36 is formed on the surface of the substrate original sheet 43 which is the side of the vibrating plate 31, and the lower electrode layer 36 is patterned by the photolithography step and the etching step. Similarly, the piezoelectric element 32 is formed on the substrate original sheet 43 by sequentially forming the piezoelectric layer 37, the upper electrode layer 38, and the metal layer 39 (see FIG. 6(a)). Further, in the piezoelectric element 32, the tensile force generated by the layer constituting the piezoelectric element 32 causes the force to be bent toward the side opposite to the original substrate 43 to act, but the rigidity of the original substrate 43 is higher. High, so it is not deformed.

When the piezoelectric element 32 is formed on the substrate original sheet 43, the polishing step is moved. In the polishing step, the substrate which becomes the pressure chamber forming substrate 29 is polished to the thickness of the pressure chamber forming substrate 29 (for example, about 40 to 50 μm). In this case, the region from the piezoelectric element 32 away from the piezoelectric element 32 (the region outside the opening peripheral region Ae) is pressed from the piezoelectric element 32 side in the thickness direction, and the piezoelectric element 32 side is pressed. On the opposite side, the substrate original sheet 43 is polished (cut) so that the thickness of the substrate original sheet 43 in the unpressed region (opening peripheral region Ae) is thicker than the thickness of the substrate original sheet 43 in the pressed region. In this embodiment, as shown in FIG. 6(b) The substrate original sheet 43 is pressed by pressing the pressing substrate 44 on the surface (the surface on the piezoelectric element 32 side) of the substrate original sheet 43 on the opposite side to the polishing surface. The pressing substrate 44 is provided with a hollow portion 44a recessed to the middle of the thickness direction in a portion opposed to a region corresponding to the peripheral edge region Ae of the substrate original sheet 43 so as to be pressed against the substrate original sheet 43. The piezoelectric element 32 is housed in the empty portion 44a. The outer side of the hollow portion 44a of the pressing substrate 44 is a pressing portion 44b that presses a region of the substrate original sheet 43 that is outside the region corresponding to the opening peripheral region Ae. As shown in Fig. 7 (a), when the pressing substrate 44 is pressed against the substrate original sheet 43 and the substrate original sheet 43 is polished by the CMP (Chemical Mechanical Polishing) method or the like from the opposite side, The polishing (cutting) rate of the region corresponding to the portion that is not pressed is lowered, and the thickness of the region is thicker than the thickness of the region pressed by the pressing portion 44b. Then, when the pressing substrate 44 is removed, as shown in FIG. 7(b), the substrate original sheet 43 which is not pressed is further raised toward the side opposite to the piezoelectric element 32 side than the pressed region. In other words, the thickness of the substrate original piece 43 gradually increases from the region corresponding to the position away from the piezoelectric element 32 to the region corresponding to the piezoelectric element 32.

In this state, as shown in FIG. 8(a), the sealing plate 33 is attached to the piezoelectric element 32 side of the substrate original piece 43 in a state in which the piezoelectric element 32 is housed in the piezoelectric element housing portion 41. When the sealing plate 33 has been attached to the substrate original sheet 43, it is moved to a pressure chamber forming step (corresponding to the empty chamber forming step of the present invention). In the pressure chamber forming step, the pressure chamber 30 is formed in a region where the thickness of the substrate original sheet 43 to be polished is thick, that is, a region corresponding to the piezoelectric element 32. Specifically, the photoresist is patterned by the photolithography step on the surface of the substrate original sheet 43 on the side opposite to the piezoelectric element 32 side. Then, the substrate of the substrate original sheet 43 which becomes the pressure chamber forming substrate 29 is penetrated in the thickness direction by the etching step to form the pressure chamber 30. Thereafter, when the photoresist is removed, the pressure chamber 30 is formed as shown in FIG. 8(b), and the substrate original sheet 43 serves as the pressure chamber forming substrate 29 and the diaphragm 31. That is, the pressure chamber 30 is formed, and the pressure chamber is formed such that the thickness of the pressure chamber 30 is gradually increased. Here, since the rigidity of the pressure chamber forming substrate 29 is weakened by the formation of the pressure chamber 30, the base is formed toward the pressure chamber by the piezoelectric element 32. The pressure on the opposite side of the plate 29 is bent, and the pressure chamber forming substrate 29 and the vibrating plate 31 of the opening peripheral region Ae of the pressure chamber 30 are pulled toward the piezoelectric element 32 side. In other words, a portion where the thickness of the pressure chamber forming substrate 29 is thick, that is, a portion which is raised toward the side opposite to the piezoelectric element 32 side in a state before the pressure chamber 30 is formed, is swelled toward the piezoelectric element 32 side. Thereby, the surface of the pressure chamber forming substrate 29 on the side opposite to the piezoelectric element 32 side (the joint surface with the communication substrate 24) becomes substantially flat.

Finally, in the substrate bonding step, as shown in FIG. 8(c), a portion corresponding to the piezoelectric device is formed by bonding the communication substrate 24 to the side opposite to the piezoelectric element 32 side of the pressure chamber forming substrate 29. Further, in the present embodiment, in the pressure chamber forming step, the surface of the pressure chamber forming substrate 29 opposite to the piezoelectric element 32 side is substantially flat, but the substrate is formed by the initial shape of the piezoelectric element 32 or the pressure chamber. When the pressure chamber 30 is formed, the surface of the pressure chamber forming substrate 29 on the side opposite to the piezoelectric element 32 side is not substantially flat. In this case, by pressing the communication substrate 24 to the pressure chamber forming substrate 29 side and joining, the surface of the pressure chamber forming substrate 29 on the side opposite to the piezoelectric element 32 side can be made substantially flat, and the pressure chamber 30 can be made. The opening peripheral edge area Ae is raised toward the piezoelectric element 32 side. In this case, since the stress in the original peripheral edge area Ae is returned to the original shape (that is, in a state of being raised toward the side of the communication substrate 24), even when the piezoelectric element 32 is deformed toward the side opposite to the vibrating plate, The peripheral edge area Ae is also not easily deformed. Therefore, the case where the pressure chamber forming substrate 29 and the communicating substrate 24 are peeled off is more reliably suppressed.

Further, in the pressure chamber forming substrate 29 of the above-described first embodiment, the entire peripheral edge area Ae of the pressure chamber 30, that is, the entire circumference of the opening periphery of the pressure chamber 30 is thicker than the area of the outer side of the opening peripheral area Ae. It is formed to be thicker, but is not limited to this. It suffices that the thickness of at least a part of the peripheral edge region of the pressure chamber of the pressure chamber forming substrate is thicker than the region of the outer side of the opening peripheral region. Further, in the pressure chamber forming substrate 29 of the above-described first embodiment, the thickness of the entire peripheral edge region Ae of the pressure chamber 30 is gradually increased toward the pressure chamber 30, but the invention is not limited thereto. At least a part of the peripheral edge region of the pressure chamber of the pressure chamber forming substrate may be gradually thickened toward the thickness of the pressure chamber. Furthermore, In the pressure chamber forming substrate 29 of the above-described first embodiment, the regions other than the opening peripheral region Ae of the pressure chamber 30 are set to have substantially the same plate thickness, but the invention is not limited thereto. For example, the thickness of one portion of the pressure chamber forming substrate in the region other than the peripheral region of the opening of the pressure chamber may be increased. In short, it is sufficient that the thickness of the peripheral edge region of the pressure chamber of the pressure chamber forming substrate is thicker than the thickness of at least a portion of the outer region of the opening peripheral region.

For example, in the pressure chamber forming substrate 29' (piezoelectric device) of the second embodiment shown in Fig. 9, the thickness of the region around the opening of the pressure chamber 30' and the region between them are increased. In addition, in FIG. 9, the area|region which thickened a board|substrate is shown by hatching. Specifically, in the pressure chamber forming substrate 29' of the second embodiment, the thickness of the pressure chamber 30' is increased from the outer side in the longitudinal direction of the pressure chamber 30' to the pressure chamber 30'. That is, the width of the longitudinal direction of the pressure chamber 30' is wider, that is, the strip-shaped region (except the pressure chamber 30') extending in the direction in which the piezoelectric elements 32 are arranged is more outward than the region. The plate thickness of the area is thicker. Further, in the strip-shaped region, an opening peripheral region of the pressure chamber 30' is included. In the present embodiment, the thickness of the pressure chamber forming substrate 29' is substantially constant in the direction of the nozzle row direction (that is, the direction in which the pressure chambers 30' are arranged). Further, when the arrangement of the pressure chambers 30' is a narrow pitch (for example, 600 dpi) as in the present embodiment, the region sandwiched between the adjacent pressure chambers 30' can also be regarded as the peripheral periphery of each pressure chamber 30'. region. That is, the above-mentioned strip-shaped region may be regarded as being connected to the peripheral edge region of each of the pressure chambers 30'. The other configuration is the same as that of the first embodiment described above, and thus the description thereof is omitted.

Next, a method of manufacturing the piezoelectric device of the second embodiment will be described. Further, even in the piezoelectric device of the second embodiment, it can be produced in the same manner as the manufacturing method of the first embodiment, and a simpler manufacturing method will be described here. First, similarly to the manufacturing method of the first embodiment, a layer serving as the vibrating plate 31 is formed on a substrate (for example, a ruthenium substrate) serving as the pressure chamber forming substrate 29', and the pressure chamber forming substrate 29' and the vibrating plate 31 are formed. Substrate original sheet 43'. When the substrate original sheet 43' is formed, the manufacturing method of the first embodiment is the same as that of the first embodiment. In the piezoelectric element forming step, the piezoelectric element 32 is formed on the surface of the substrate original piece 43' which is the side of the vibrating plate 31 (see FIG. 10(a)). When the piezoelectric element 32 is formed on the substrate original piece 43', as shown in Fig. 10 (b), the sealing plate 33 is attached to the surface of the substrate original piece 43' on the piezoelectric element 32 side. In the production method of the present embodiment, the state is moved to the polishing step in this state.

In the polishing step, the sealing plate 33 is pressed from the top plate portion 33a side, and is polished into a substrate of the pressure chamber forming substrate 29'. The side wall portion 33b of the sealing plate 33 is abutting on the outer side of the longitudinal direction of the piezoelectric element 32 of the substrate original piece 43', and abuts against the arrangement direction (nozzle column direction) along the piezoelectric element 32. Therefore, the area is pressed. In the same manner as in the manufacturing method of the first embodiment, the substrate original sheet 43' is polished (cut) from the side opposite to the piezoelectric element 32 side in a state where the sealing plate 33 is pressed from the side of the piezoelectric element 32, so that the substrate is not pressed. The thickness of the substrate original sheet 43' in the region is thicker than the thickness of the substrate original sheet 43' in the pressed region. As a result, as shown in FIG. 10(a), a region in which the unpressed region (the region corresponding to the piezoelectric element housing portion 41) is raised toward the side opposite to the piezoelectric element 32 side from the pressed region is formed. Original piece 43'. That is, the thickness of the substrate original piece 43' is gradually increased from the region corresponding to the position away from the piezoelectric element 32 to the region corresponding to the piezoelectric element 32.

When the substrate original sheet 43' has been polished, similarly to the manufacturing method of the first embodiment, in the pressure chamber forming step, the thickness of the substrate original sheet 43' to be polished is thick, that is, the piezoelectric element 32. The corresponding area forms a pressure chamber 30'. Thereby, as shown in FIG. 10(b), the pressure chamber 30' is formed, and the substrate original piece 43' becomes the pressure chamber forming substrate 29' and the diaphragm 31. That is, the pressure chamber 30' is formed, and the pressure chamber is formed to form the substrate 29' from the outer side of the pressure chamber 30' toward the pressure chamber 30'. Here, in the present embodiment, since the rigidity of the pressure chamber forming substrate 29' is weakened by the formation of the pressure chamber 30', the substrate 29' is formed opposite to the pressure chamber by the piezoelectric element 32. The pressure on the side is bent, and the pressure chamber forming substrate 29' and the vibrating plate 31 on the outer side of the pressure chamber 30' are stretched toward the piezoelectric element 32 side. In other words, a portion of the pressure chamber forming substrate 29' having a thick thickness, that is, a portion which is raised toward the side opposite to the piezoelectric element 32 side in a state before the pressure chamber 30' is formed, is swelled toward the piezoelectric element 32 side. Therefore, in the present embodiment, the surface of the pressure chamber forming substrate 29' opposite to the piezoelectric element 32 side is also substantially flat. Finally, in the substrate bonding step, as shown in FIG. 10(c), the piezoelectric substrate is formed by bonding the communication substrate 24 to the side opposite to the piezoelectric element 32 side of the pressure chamber forming substrate 29'. section.

As described above, in the manufacturing method of the present embodiment, since the substrate original sheet 43' is pressed by the sealing plate 33, unlike the manufacturing method of the first embodiment, it is not necessary to separately press the substrate original sheet 43' using the pressing substrate 44. Reduce manufacturing steps. As a result, it is possible to easily produce a piezoelectric device that suppresses peeling of the pressure chamber forming substrate 29' and the communication substrate 24 and improves reliability.

Further, in each of the above embodiments, the pressure chambers 30 and 30' are formed in a substantially parallelogram shape in plan view, but the present invention is not limited thereto. For example, a plurality of shapes such as a rectangular shape, a trapezoidal shape, a circular shape, and an elliptical shape can be adopted in a plan view. In short, regardless of the shape of the pressure chamber, it is sufficient that the thickness of at least a portion of the peripheral region of the opening of the pressure chamber forming the substrate of the pressure chamber is thicker than the thickness of the region outside the peripheral portion of the opening. Further, at least a part of the peripheral edge region of the pressure chamber of the pressure chamber forming substrate may be gradually thickened toward the thickness of the pressure chamber.

In the above, the piezoelectric device includes a configuration in which the communication substrate 24 including the recording head 3, the pressure chamber forming substrate 29, the vibration plate 31, and the piezoelectric element 32 are described as an example. However, the present invention can also be applied to formation. The first substrate having the empty chamber, the piezoelectric element in which the vibrating plate is interposed in the empty chamber, and the other piezoelectric device laminated on the second substrate on the side opposite to the piezoelectric element side of the first substrate. Further, the liquid ejecting head can be formed, for example, as a color material ejecting head for manufacturing a color filter such as a liquid crystal display, or an electrode for use in an organic EL (Electro Luminescence) display or an FED (Face Light Emitting Display). The present invention is applied to an electrode material ejection head, a biological organic matter ejection head used for the production of a biochip (biochemical element), and the like.

24‧‧‧Connected substrate

29‧‧‧ Pressure chamber forming substrate

30‧‧‧ Pressure chamber

31‧‧‧Vibration plate

32‧‧‧Piezoelectric components

33‧‧‧ Sealing plate

33a‧‧‧Top Board

33b‧‧‧ Sidewall

41‧‧‧ Piezoelectric component storage

Ae‧‧‧Open Peripheral Area

Ta‧‧‧distance

Ta'‧‧‧ plate thickness

Tb‧‧‧ plate thickness

Claims (6)

A piezoelectric device comprising: a first substrate formed with an empty chamber; a vibration plate that faces a surface on one side of the empty chamber; and a piezoelectric element attached to the vibrating plate opposite to the empty chamber a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially stacked from the side of the vibrating plate; and the second substrate is laminated on a side opposite to the vibrating plate side of the first substrate; At least a portion of the peripheral edge region of the opening of the empty chamber of the first substrate is thicker than a region of the outer region of the opening peripheral region. The piezoelectric device according to claim 1, wherein the entire circumference of the opening peripheral region is thicker than the outer portion of the opening peripheral region. A piezoelectric device comprising: a first substrate formed with an empty chamber; a vibration plate that faces a surface on one side of the empty chamber; and a piezoelectric element attached to the vibrating plate opposite to the empty chamber a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially stacked from the side of the vibrating plate; and the second substrate is laminated on a side opposite to the vibrating plate side of the first substrate; At least a portion of the first substrate gradually increases in thickness toward the empty chamber. A liquid ejecting head comprising: the piezoelectric device according to any one of claims 1 to 3; and a nozzle connected to the empty chamber. A method of manufacturing a piezoelectric device, comprising: a first substrate formed with an empty chamber; a vibrating plate that divides a surface on one side of the empty chamber; a piezoelectric element that is disposed on a side opposite to the empty chamber of the vibrating plate, and sequentially stacks the first electrode layer and the piezoelectric layer from the side of the vibrating plate And the second electrode layer; and the second substrate is laminated on a side opposite to the vibration plate side of the first substrate; and the method of manufacturing the piezoelectric device includes a piezoelectric element forming step, wherein Forming the piezoelectric element on a surface of the original substrate of the first substrate and the vibrating plate on the side of the vibrating plate, and performing a polishing step of self-pressing the region of the substrate original from the piezoelectric element In a state in which the electric component side is pressed in the thickness direction, the substrate original sheet is polished from the side opposite to the piezoelectric element side, and the substrate original sheet of the region where the substrate original sheet is not pressed in the unpressed region is pressed. a thicker plate forming step of forming the empty space in a region where the thickness of the original substrate of the substrate is thick, that is, a region corresponding to the piezoelectric element, and the original substrate is set as The first substrate and the upper substrate Vibration plate; and a substrate bonding step, the second substrate which is the opposite side of the side of the piezoelectric element is bonded to the first substrate. The method of manufacturing a piezoelectric device according to claim 5, wherein in the polishing step, the unpressed region of the substrate original sheet is raised toward the side opposite to the piezoelectric element side from the pressed region.